Adds tweaks to run MNAIO on Ubuntu 18.04

Drops python-software-properties package as it
doesn't appear to be in the Bionic build.

Change-Id: I70ee08b69374e7e61a6ac3344a93f119748941e9

multi-node-aio/README.rst

@@ -20,7 +20,7 @@ Process
 -------
 
 Create at least one physical host that has public network access and is running
-the Ubuntu 14/6.04 LTS Operating system. System assumes that you have an
+an Ubuntu 14.04/16.04/18.04 LTS Operating system. System assumes that you have an
 unpartitioned device with at least 1TB of storage, however you can customize the
 size of each VM volume by setting the option ``${VM_DISK_SIZE}``. If you're
 using the Rackspace OnMetal servers the drive partitioning will be done for you

multi-node-aio/playbooks/vars/ubuntu-18.04.yml

@@ -0,0 +1,56 @@
+---
+# Copyright 2018, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in witing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+mnaio_host_required_distro_packages:
+  - ubuntu-cloud-keyring
+
+mnaio_host_package_repos:
+  - repo: "deb http://ubuntu-cloud.archive.canonical.com/ubuntu {{ ansible_lsb.codename }}-updates/queens main"
+    state: present
+    filename: "uca"
+    condition: "{{ ansible_lsb.codename == 'xenial' }}"
+
+mnaio_host_distro_packages:
+  - bridge-utils
+  - ifenslave
+  - iptables-persistent
+  - libvirt-bin
+  - lvm2
+  - ntp
+  - openssh-server
+  - python2.7
+  - python-lxml
+  - qemu-kvm
+  - qemu-utils
+  - software-properties-common
+  - virtinst
+  - virt-manager
+  - vlan
+
+mnaio_pxe_distro_packages:
+  - tftpd-hpa
+  - inetutils-inetd
+  - nginx
+  - p7zip-full
+
+mnaio_dhcp_distro_packages:
+  - isc-dhcp-server
+
+mnaio_pkg_cache_server_distro_packages:
+  - apt-cacher-ng
+
+mnaio_host_iptables_service: "{{ (ansible_distribution | lower + '-' + ansible_distribution_version | lower == 'ubuntu-14.04') | ternary('iptables-persistent', 'netfilter-persistent') }}"
+
+ssh_service_name: ssh